Methods and systems for monitoring a temperature of a component during a welding operation

ABSTRACT

A method of monitoring a heating operation on an component by a flame torch, including the steps of producing a flame with the flame torch, rotating the component with respect to the flame so that a circular weld is created on the component, and providing a first sensor that is operatively engaged with the component so that the first sensor monitors rotation or non-rotation of the components.

FIELD OF THE INVENTION

The present invention relates generally to heating operations thatfacilitate welding operations to meet specification requirements. Moreparticularly, the present invention relates to systems and methods ofmonitoring heating operations that facilitate welding operations to meetspecification requirements.

BACKGROUND OF THE INVENTION

To help insure even heat distribution and weld creation on cylindricalcomponents, it is known to rotate the component with regard to thewelding assembly as the weld is created. Current methods for verifyingand controlling the temperature of the component in the vicinity of theweld while under flame heating typically require the use of temperaturecrayons and/or pyrometers that are placed in direct contact with thesurface of the component. Based on the information gathered by thetemperature crayons and/or pyrometers, an operator adjusts the flameintensity of the welding assembly by manually adjusting the flow of fuel(i.e., natural gas, etc.) from its fuel source. Checking componenttemperatures and the corresponding adjustment of the welding flametypically occur a finite number of times over the time interval requiredfor the creation of the weld. For example, temperature verification mayoccur hourly, bi-hourly, etc., during weld creation. This infrequenttemperature verification and welding flame adjustment can lead totemperature excursions in the weld zone that are both above and/or belowtemperature set points that are required per specification requirementsand, therefore, approval of the component for its intended use.Additionally, if rotation of the component during welding ceases andgoes unnoticed by the operator, localized overheating may occur whichcan lead to the component being damaged to the extent that it cannotmeet prescribed standards for its desired use.

Such welding operations typically include a “preheat stage” prior tocreation of the weld, as well as a “post-bake stage” after weldcreation. The preheat stage is required to bring the temperature of thecomponent up to a minimum temperature limit at which weld creation canbe commenced. In the post-bake stage the component temperature iselevated to a predetermined amount above the temperature at which theweld is created to help insure hydrogen is diffused from the weld andsurrounding base material, helping to prevent hydrogen cracking. It isimportant that temperature excursions beyond the upper and lowertemperature set points are prevented during all three phases of the weldoperation.

The present invention recognizes and addresses considerations of priorart constructions and methods.

SUMMARY OF THE INVENTION

One embodiment of the present disclosure provides a method of monitoringa heating operation on a component by a flame torch, including the stepsof producing a flame with the flame torch, rotating the component withrespect to the flame so that a circular weld is created on thecomponent, and providing a first sensor that is operatively engaged withthe component so that the first sensor monitors rotation or non-rotationof the components.

Another embodiment of the present disclosure provides a method ofmonitoring a heating operation on a component by a flame torch,comprising the steps of producing a flame with the flame torch, rotatingthe component with the respect to the flame so that a circular weld iscreated on the component, and providing a first sensor that isoperatively engaged with the component so that the first sensor monitora temperature of the component in a vicinity of the circular weld.

Another embodiment of the present disclosure provides a system formonitoring a heating operation on a component by a flame torch, thesystem including a first sensor that is operatively engaged with thecomponent, the first sensor being configured to detect rotation ornon-rotation of the component and produce a first electrical signal thatis indicative of the rotation or non-rotation of the component. A secondsensor is operatively engaged with the component and is configured todetect a temperature of the component and produce a second electricalsignal that is indicative of the temperature of the component. Aprocessor is configured to both receive the first electrical signal andproduce an audible alarm based on the first electrical signal indicatingnon-rotation of the component, and receive the second electrical signaland produce an audible alarm when the temperature of the component isgreater than a pre-determined temperature value.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate one or more embodiments of theinvention and, together with the description, serve to explain theprinciples of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendeddrawings, in which;

FIG. 1 is a schematic view of an embodiment of a system for monitoring aheating operation on a component in accordance with the presentdisclosure;

FIG. 2 is a cross-sectional view of the system for monitoring a heatingoperation shown in FIG. 1, taken along line 2-2; and

FIG. 3 is a flow chart showing an ignition sequence of a flame torch ofthe heating system shown in FIGS. 1 and 2.

Repeat use of reference characters in the present specification anddrawings is intended to represent same or analogous features or elementsof the invention according to the disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to presently preferred embodimentsof the invention, one or more examples of which are illustrated in theaccompanying drawings. Each example is provided by way of explanation,not limitation, of the invention. In fact, it will be apparent to thoseskilled in the art that modifications and variations can be made in thepresent invention without departing from the scope and spirit thereof.For instance, features illustrated or described as part of oneembodiment may be used on another embodiment to yield a still furtherembodiment. Thus, it is intended that the present invention covers suchmodifications and variations as come within the scope of the appendedclaims and their equivalents.

Referring now to the figures, as shown in FIGS. 1 and 2, an embodimentof a welding system in accordance with the present disclosure includes aprogrammable logic controller 112, a plurality of temperature sensors116 for determining temperatures of a welded component 130, a rotationsensor 120 for determining whether or not the component is beingrotated, an ultrasonic sensor 122 for determining component creep, and aflame torch assembly 134 including a flame sensor 137. Preferably,programmable logic controller 112 monitors component temperatures, thestatus of the flame, rotation of the welded component, and componentcreep relative to its longitudinal center axis. However, in alternateembodiments, more than one programmable logic controller may be used tomonitor these functions.

When creating a circular weld on a cylindrical component 130, component130 is rotated to help insure even heating of the component surface andeven deposition of weld material along circular weld 140. As such,component 130 is supported on multiple rollers, as best seen in FIG. 2.In the instant case, component 130 is supported on a drive roller 131and an idler roller 132. Preferably, rotation sensor 120 is placed inrolling engagement with idler roller 132. An example rotation sensor 120is a magnetic encoder device, such as Model No. Z001000A, manufacturedby Red Lion, that allows programmable logic controller 112 to recognizethe status of rotation of component 130 on rollers 131 and 132.Specifically, programmable logic controller 112 utilizes the signal fromthe magnetic encoder to determine a binary result, which is indicativeof whether or not rotation sensor 120 detects rotation of idler roller132. Rotation sensor 120 is preferably placed in contact with idlerroller 132 because idler roller 132 only rotates when component 130 isrotating. In contrast, if rotation sensor 120 is operatively engagedwith drive roller 131, it is possible that the sensor would appear toindicate rotation of component 130 as it would actually be monitoringrotation of drive roller 131, even if slippage is occurring betweendrive roller 131 and component 130. Note, however, in alternateembodiments a rotation sensor can be placed in operative engagement withboth idler roller 132 and component 130. Upon an indication fromrotation sensor 120 that component 130 is not rotating, programmablelogic controller 112 creates both an audible and visual alarm toindicate that operator intervention is required.

Referring now to FIG. 1, an ultrasonic sensor 122 is used to monitoraxial movement, or creep, of component 130 on drive roller 131 and idlerroller 132 relative to a longitudinal center axis 131 of component 130.Preferably, ultrasonic sensor 122 is placed a predetermined distance (d)from an end of component 130. As component 130 is rotated, ultrasonicsensor 122 monitors a distance between itself and the end of component130. If the distance between ultrasonic sensor 122 and component 130deviates from predetermined distance (d) by a selected amount,programmable logic controller 112 provides an audible and visual alarmto indicate that operator intervention may be required. Preventingcomponent creep is important during welding operations to insure notonly that the component being welded is not damaged, such as by fallingoff the rollers, but to also insure that various monitoring devicesdisposed on the component, such as temperature sensors 116 are notdamaged, as discussed in greater detail below.

As best seen in FIG. 1, temperature sensors 116 are secured to thesurface of component 130 adjacent circular weld 140. Preferably, eachtemperature sensor 116 is a K-type thermocouple that is secured to theouter surface of component 130 by a corresponding magnet. Note, however,temperature sensors 116 may be secured to component by tack welding,epoxies, etc., in alternate embodiments. Each temperature sensor 116 isconnected to a corresponding wireless transmitter 118 that transmits thesensor's temperature measurements to programmable logic controller 112.An example of wireless transmitter 118 is Model No. UWTC-2, manufacturedby Omega Engineering. The positions of both temperature sensors 116 andwireless transmitters 118 on the component are selected so that theywill not be damaged by drive roller 131 and idler roller 132.Additionally, each temperature sensor 116 is covered with a layer ofinsulation material so that the temperature sensors measure thetemperature of component 130 in the vicinity of circular weld 140 andnot the temperature of welding flame 136.

Wireless transmitters 118 allow component 130 to be rotated withouthaving to account for the wires that would otherwise connect temperaturesensors 116 to programmable logic controller 112. Wireless transmitters118 are battery powered, and are preferably uniquely addressed to theprogrammable logic controller. By uniquely addressing each wirelesstransmitter 118 to the programmable logic controller, nocross-communication will occur in the event that multiple weldingoperations are being simultaneously monitored in close proximity to eachother. Preferably, a human machine interface (HMI) or personal computer(PC) (not shown) interfaces with programmable logic controller 112 andmaintains the history of the component temperatures as measured bytemperature sensors 118 over the duration of the welding operation,including both preheat and post-bake stages. The temperature historyfacilitates determination of whether or not a component may be clearedfor its intended use in the event that a temperature excursion doesoccur during the welding operation.

Still referring to FIG. 1, flame torch assembly 134 includes a fuelsource 138, such as natural gas, and flame sensor 137 for determiningthe presence or absence of welding flame 136 during welding operations.An example of flame sensor 137 is Model No. 39F95, manufactured byLennox. Flame sensor 137 provides a signal to programmable logiccontroller 112 that indicates whether flame 136 is present. As discussedin greater detail below, programmable logic controller 112 uses thisinformation to either initiate an automatic ignition sequence for flametorch assembly 134, or in the case of multiple failed ignitionsequences, to secure the flow of fuel from fuel source 138 to flametorch assembly 134. Securing the flow of fuel from fuel source 138prevents the inadvertent buildup of fuel should flame 136 becomeunintentionally extinguished. Note, flame torch assembly 134 preferablyincludes multiple flames (i.e., eight or more) that are typicallyarranged in a semi-circular configuration.

Referring now to FIG. 3, an example of a heating operation utilizing thedisclosed heating system is discussed. First, the operator initiates theheating operation by way of programmable logic controller 112, step 200.Next, the programmable logic controller performs a system check, step202. Specifically, programmable logic controller 112 determines ifrotation of component 130 is detected and whether ultrasonic sensor 122is active. Programmable logic controller 112 verifies that signals arebeing received from wireless transmitters 118 and that fuel pressure isdetected at flame torch assembly 134. If any of these checks arenegative, the programmable logic controller prompts the operator forcorrective action, step 204. If the system check is positive,programmable logic controller 112 prompts the operator for operationalsettings, step 206. In the present case, the operational settingsinclude a lower temperature limit (LTL) and an upper temperature limit(UTL) that are not to be violated during the welding operation.Additionally, a value of the thermocouple accuracy (TA) is entered foruse in determine warning ranges that are used during the weldingoperation. Specifically, green, yellow and red visual warnings areprovided by programmable logic controller 112, with each visualindication corresponding to various temperature ranges of the componentssurface. For example, for a welding operation in which LTL=200° F. andUTL=650° F., a range of temperatures for which a green visual indicationis provided is determined by the equation LTL+TA+50°<L Tavg2<UTL-TA−50°F., where the 50° value is a safety buffer selected by the operator andTavg2 is determined by rejecting the highest reading of the flowtemperature sensors 116 and averaging the remaining three readings. Theresultant range is 275° to 575° F. A range of temperatures for which ayellow visual indication is provided is determined by the equationLTL+TA<Tavg2<UTL-TA. The resultant temperature ranges for which a yellowvisual indication is provided is 225° to 275° F. and 575° to 625° F. Ared visual indication is provided when Tavg2 comes within the value ofthe thermocouple accuracy (TA) of the LTL and UTL. Note, audiblewarnings may also be provided in additional to the green, yellow and redvisual indications.

After operational settings have been entered, programmable logiccontroller 112 prompts the operator for approval to initiate theignition sequence of flame torch assembly 134, step 208. Once approvalis received, programmable logic controller 112 executes an ignitionsequence in which fuel is provided to flame torch assembly 136 from fuelsource 138 and a direct spark ignition system is activated. Note, apilot flame may be utilized rather than a direct spark ignition systemso that flame 136 is created upon the initiation of flow of fuel toflame torch assembly 134. Next, programmable logic controller 112determines whether flame 136 has been successfully ignited, step 212, asdetermined by input from flame sensor 137. If flame 136 is not present,programmable logic controller 112 will execute the ignition sequenceanother time, step 214. If after two attempts, step 216, flame 136 isnot present, first programmable logic control 112 secures the flow offuel to torch assembly 134, step 218, and prompts the operator forcorrective action, step 204.

Once the ignition sequence is determined to be successful and flame 136is produced, a preheat stage commences in which the area of component130 to be welded is brought up to the lower temperature limit (LTL),step 220. During the preheat stage of component 130, the status of flame136 is continuously monitored, step 222. As before, if programmablelogic controller 112 determines that flame 136 is not present based oninput from flame sensor 137, the controller will automatically executethe ignition sequence, steps 226 and 210. If flame 136 is notestablished after two ignition sequence attempts, step 224, programmablelogic controller 112 will automatically secure the flow of fuel to flametorch assembly 134, step 218, and prompt the operator for correctiveaction, step 204. If flame 136 remains established during the preheatstage, and Tavg2 is greater than LTL for greater than two minutes, step228, the welding stage will commence.

During the welding stage, programmable logic controller 112 monitors theplurality of temperature sensors 116 and determines Tavg1, which is theaverage of the readings of all the temperature sensors, step 230.Programmable logic controller 112 records the temperature history ofcomponent 130 and compares Tavg1 to the above described temperatureranges that are used to determine whether programmable logic controller112 provides a green, yellow or red visual indication. As well,programmable logic controller 112 utilizes Tavg1 to automatically adjustthe intensity of flame 136 by way of adjusting the flow of fuel to flametorch assembly. As such, programmable logic controller 112 maintainscomponent temperatures within the prescribed limits during the weldingoperation. Programmable logic controller 112 continues to monitor theplurality of temperature sensors 118 and record the temperature historycontinuously during the welding stage as well as the post-bake stage, atwhich point the welding operation is completed.

While one or more preferred embodiments of the invention are describedabove, it should be appreciated by those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope and spirit thereof. It is intended thatthe present invention cover such modifications and variations as comewithin the scope and spirit of the appended claims and theirequivalents.

What is claimed is:
 1. A method of monitoring a heating operation on acomponent by a flame torch, comprising the steps of: producing a flamewith the flame torch; rotating the component with respect to the flameso that a circular weld is created on the component; and providing afirst sensor that is operatively engaged with the component so that thefirst sensor monitors rotation or non-rotation of the components.
 2. Themethod of claim 1, further comprising the step of providing an audiblealarm in response to the first sensor detecting non-rotation of thecomponent.
 3. The method of claim 1, further comprising the step ofproviding a second sensor that monitors a presence or an absence of theflame during the heating operation.
 4. The method of claim 3, furthercomprising the step of attempting to light the flame torch in responseto the second sensor detecting the absence of the flame.
 5. The methodof claim 4, further comprising the step of securing a fuel source of theflame torch in response to a failed attempt to light the flame torch. 6.The method of claim 4, further comprising the step of producing anaudible alarm while attempting to light the flame torch.
 7. The methodof claim 2, further comprising the step of providing a third sensor thatmonitors a temperature of the component in a vicinity of the circularweld.
 8. The method of claim 6, further comprising the step ofcontrolling a temperature of the flame in response to the temperature ofthe component monitored by the third sensor.
 9. The method of claim 7,further comprising the step of securing the fuel source to the flametorch in response to the temperature of the component monitored by thethird sensor.
 10. The method of claim 1, further comprising the stepsof: providing a fourth sensor at a known distance from a first end ofthe component, the known distance being parallel to a longitudinalcenter axis of the component; monitoring a measured distance between thefourth sensor and the first end of the component; and stopping rotationof the component and production of the flame with the flame torch whenthe measured distance differs from the known distance by a selectedamount.
 11. The method of claim 10, further comprising the step ofproducing an audible alarm when the measured distance of the fourthsensor from the component exceeds the selected value.
 12. A method ofmonitoring a heating operation on a component by a flame torch,comprising the steps of: producing a flame with the flame torch;rotating the component with the respect to the flame so that a circularweld is created on the component; and providing a first sensor that isoperatively engaged with the component so that the first sensor monitorsa temperature of the component in a vicinity of the circular weld. 13.The method of claim 12, further comprising the step of controlling atemperature of the flame in response to the temperature of the componentmonitored by the first sensor.
 14. The method of claim 12, furthercomprising the step of securing the fuel source to the flame torch inresponse to the temperature of the component monitored by the firstsensor.
 15. The method of claim 12, further comprising the step ofproviding a second sensor that monitors rotation or non-rotation of thecomponent.
 16. The method of claim 15, further comprising the step ofproviding an audible alarm in response to the second sensor detectingnon-rotation of the component.
 17. The method of claim 12, furthercomprising step of providing a third sensor that monitors a presence oran absence of the flame during the heating operation.
 18. The method ofclaim 17, further comprising the steps of; attempting to light the flametorch in response to the third sensor detecting the absence of theflame; and securing a fuel source of the flame torch in response to afailed attempt to light the flame torch.
 19. A system for monitoring aheating operation on a component by a flame torch, the systemcomprising: a first sensor that is operatively engaged with thecomponent, the first sensor being configured to detect rotation ornon-rotation of the component and produce a first electrical signal thatis indicative of the rotation or non-rotation of the component; a secondsensor that is operatively engaged with the component, the second sensorbeing configured to detect a temperature of the component and produce asecond electrical signal that is indicative of the temperature of thecomponent; and a processor that is configured to receive the firstelectrical signal and produce an audible alarm based on the firstelectrical signal indicating non-rotation of the component, and receivethe second electrical signal and produce an audible alarm when thetemperature of the component is greater than a pre-determinedtemperature value.
 20. The method of claim 19, further comprising athird sensor that is configured to detect a presence or an absence of aflame and produce a third signal that is indicative of the presence orthe absence of the flame, wherein the processor is configured to receivethe third electrical signal and produce an audible alarm based on thethird electrical signal indicating the absence of the flame.